Zebby Matthews Has Grade 2 Subscapularis Strain: How Long Will Minnesota Twins Be Without Young Hurler? – Twins

The Minnesota Twins lost another starting pitcher for the foreseeable future when they placed Zebby Matthews on the 15-day IL with what was initially reported as a “shoulder strain.” The Twins provided more details on Tuesday evening, revealing that the righty suffered a moderate strain of his subscapularis and that he will be shut down from throwing for two weeks.

The subscapularis is one of the four rotator cuff muscles, and it’s located on the front side of the scapula, or shoulder blade, situated between the scapula and rib cage. Its purpose is to forcefully internally rotate the humerus, or arm bone. In layman’s terms, it is one of the muscles that generates significant power, allowing for throwers to achieve a high velocity. It functions similarly to the teres major, the muscle that recently landed fellow starter Pablo Lopez on the IL. However, the teres major is arguably a more complex muscle, as it performs two actions, shoulder internal rotation and extension, which generally extends the return-to-play timeline slightly.

Regardless, it would not surprise me if Matthews ultimately misses a similar amount of time as Lopez. A moderate strain, also sometimes called a Grade 2 strain, is generally a weeks-to-months injury, and the Twins will undoubtedly want Matthews to go on a rehab assignment following his recovery. The location of the strain will be one of the primary drivers of his timeline. Torn tendon fibers generally take longer to recover from than torn muscle fibers, because of their relative lack of blood flow. 

According to Baseball Prospectus’s Injury Ledger, the average time to return from a subscapularis strain is 103 days, although it’s very rare that these injuries are logged with enough detail to be sure; the sample is too small.

Luckily, Grade 2 strains don’t require surgery, though a platelet-rich plasma (PRP) injection or equivalent may be utilized to theoretically aid the healing process. There have been a huge number of shoulder strains (the initial and official category under which Matthews’s injury will be logged) from which pitchers returned within a month or so, but with this one being Grade 2, the expectation should be that he’s on the shelf until at least the end of July.

Like López, if all goes well, Matthews should be able to return to the Twins rotation before the end of the regular season. In the meantime, Minnesota will have to rely on its Triple-A depth and bullpen. While the news could be worse and Matthews does appear to have dodged the need for surgery, this is going to be a longer absence than the team initially seemed inclined to say.